Made Flags cdef class, used typed members, and typed functions, added __eq__

Support for `__eq__` allows to compare two instances of Flags objects and
compare Flags object to an integer.

Author: oleksandr-pavlyk

dpctl/tensor/_flags.pyx

@@ -18,16 +18,26 @@
 # cython: language_level=3
 # cython: linetrace=True
 
+from libcpp cimport bool as cpp_bool
+
 from dpctl.tensor._usmarray cimport (
     USM_ARRAY_C_CONTIGUOUS,
     USM_ARRAY_F_CONTIGUOUS,
     USM_ARRAY_WRITEABLE,
+    usm_ndarray,
 )
 
 
-class Flags:
+cdef cpp_bool _check_bit(int flag, int mask):
+    return (flag & mask) == mask
+
 
-    def __init__(self, arr, flags):
+cdef class Flags:
+    """Helper class to represent flags of :class:`dpctl.tensor.usm_ndarray`."""
+    cdef int flags_
+    cdef usm_ndarray arr_
+
+    def __cinit__(self, usm_ndarray arr, int flags):
         self.arr_ = arr
         self.flags_ = flags
 
@@ -37,32 +47,29 @@ class Flags:
 
     @property
     def c_contiguous(self):
-        return ((self.flags_ & USM_ARRAY_C_CONTIGUOUS)
-                == USM_ARRAY_C_CONTIGUOUS)
+        return _check_bit(self.flags_, USM_ARRAY_C_CONTIGUOUS)
 
     @property
     def f_contiguous(self):
-        return ((self.flags_ & USM_ARRAY_F_CONTIGUOUS)
-                == USM_ARRAY_F_CONTIGUOUS)
+        return _check_bit(self.flags_, USM_ARRAY_F_CONTIGUOUS)
 
     @property
     def writable(self):
-        return False if ((self.flags & USM_ARRAY_WRITEABLE)
-                        == USM_ARRAY_WRITEABLE) else True
+        return _check_bit(self.flags_, USM_ARRAY_WRITEABLE)
 
     @property
     def forc(self):
-        return True if (((self.flags_ & USM_ARRAY_F_CONTIGUOUS)
-                        == USM_ARRAY_F_CONTIGUOUS)
-                        or ((self.flags_ & USM_ARRAY_C_CONTIGUOUS)
-                        == USM_ARRAY_C_CONTIGUOUS)) else False
+        return (
+           _check_bit(self.flags_, USM_ARRAY_C_CONTIGUOUS)
+           or _check_bit(self.flags_, USM_ARRAY_F_CONTIGUOUS)
+        )
 
     @property
     def fnc(self):
-        return True if (((self.flags_ & USM_ARRAY_F_CONTIGUOUS)
-                        == USM_ARRAY_F_CONTIGUOUS)
-                        and not ((self.flags_ & USM_ARRAY_C_CONTIGUOUS)
-                        == USM_ARRAY_C_CONTIGUOUS)) else False
+        return (
+           _check_bit(self.flags_, USM_ARRAY_C_CONTIGUOUS)
+           and _check_bit(self.flags_, USM_ARRAY_F_CONTIGUOUS)
+        )
 
     @property
     def contiguous(self):
@@ -83,3 +90,13 @@ class Flags:
         for name in "C_CONTIGUOUS", "F_CONTIGUOUS", "WRITABLE":
             out.append("  {} : {}".format(name, self[name]))
         return '\n'.join(out)
+
+    def __eq__(self, other):
+        cdef Flags other_
+        if isinstance(other, self.__class__):
+           other_ = <Flags>other
+           return self.flags_ == other_.flags_
+        elif isinstance(other, int):
+           return self.flags_ == <int>other
+        else:
+           return False